JP2022087679A - Nozzle head for electrostatic atomization coater - Google Patents

Abstract

To provide a nozzle head for an electrostatic atomization coater which can achieve a coating pattern different from the case of using a conventional nozzle head.SOLUTION: A nozzle head 1 for an electrostatic atomization coater has a coating chamber 2, and a plurality of nozzles 3, in which each of the plurality of nozzles 3 fluid-communicates with the coating chamber 2 on the side of a base end 31, and the plurality of nozzles 3 are provided so that one or a plurality of openings provided on the side of a tip 32 of each of the nozzles are arrayed in a straight line.SELECTED DRAWING: Figure 1

Description

The present invention relates to a nozzle head for an electrostatic atomizing coating machine.

Painting robots are widely used to automate painting of automobile bodies. As one aspect of a general painting robot, a robot in which a painting nozzle is attached to the tip of an industrial robot is widely used. As such a nozzle, those having various structures depending on the coating method are used.

For example, Japanese Patent Application Laid-Open No. 2018-8253 (Patent Document 1) discloses an electrostatic spraying device used for performing electrostatic coating method coating. The electrostatic spraying device of Patent Document 1 is provided with a nozzle head in which a plurality of nozzles are arranged in an annular shape.

Japanese Unexamined Patent Publication No. 2018-8253

As seen in the electrostatic spraying device of Patent Document 1, in the nozzle head used for electrostatic coating, the nozzles are generally arranged in an annular shape. Therefore, when painting is performed by the electrostatic coating method, the painting pattern may be felt uniformly. Further, when a nozzle head in which the nozzles are arranged in an annular shape is used, when the nozzle head is swept along the object to be coated, a place where one nozzle passes and a place where two nozzles pass occur. Therefore, it may be difficult to make the thickness of the coating film uniform.

Therefore, it is required to realize a nozzle head for an electrostatic atomizing coating machine that can realize a coating pattern different from that when a conventional nozzle head is used.

The nozzle head for an electrostatic atomizing coating machine according to the present invention is a nozzle head for an electrostatic atomizing coating machine including a coating chamber and a plurality of nozzles, and each of the plurality of nozzles is said to be on the proximal end side. The plurality of nozzles are fluidly communicated with the paint chamber, and the plurality of nozzles are characterized in that openings provided on the tip end side of each nozzle are provided so as to be arranged in a straight line.

According to this configuration, the nozzles are arranged in a straight line. As a result, it is possible to realize a coating pattern different from the case of using the conventional nozzle head in which the nozzles are arranged in an annular shape.

Hereinafter, preferred embodiments of the present invention will be described. However, the scope of the present invention is not limited by the preferred embodiments described below.

In one aspect of the nozzle head for an electrostatic atomizing coating machine according to the present invention, the plurality of nozzles are arranged at the highest position when the linear rows of the plurality of nozzles are parallel to the vertical direction. The connection between the first nozzle and the paint chamber when the linear row of the plurality of nozzles is parallel to the vertical direction, including the first nozzle and the second nozzle arranged at the lowest position. It is preferable that the difference between the first water head, which is the water head in the portion, and the second water head, which is the water head in the connection portion between the second nozzle and the paint chamber, is within 10% of the second water head.

According to this configuration, the difference in the amount of paint discharged from each nozzle can be within 10%. As a result, uneven coating can be suppressed.

As one aspect of the nozzle head for an electrostatic atomizing coating machine according to the present invention, it is preferable that the nozzle has an inner diameter of 0.2 to 1.0 mm and a length of 5 to 100 mm.

According to this configuration, coating unevenness can be further suppressed.

As one aspect of the nozzle head for an electrostatic atomizing coating machine according to the present invention, it is preferable that electrodes are provided on extension lines of each end of a linear row of the plurality of nozzles.

According to this configuration, the electrical environment of each nozzle can be made uniform. As a result, the mode in which the paint is ejected from each nozzle (size of paint droplets, flight direction, etc.) becomes uniform, and the coating quality can be stabilized.

As one aspect of the nozzle head for an electrostatic atomizing coating machine according to the present invention, it is preferable that the tips of the electrodes are insulated from each other.

According to this configuration, it is possible to suppress the occurrence of overcurrent abnormality due to the discharge generated from the tip of the electrode.

As one aspect of the nozzle head for an electrostatic atomizing coating machine according to the present invention, at least one of the plurality of nozzles has a first portion on the proximal end side and a second portion on the distal end side. The first portion is preferably made of a material having a volume resistivity of 10 ¹² Ω · cm or less, and the second part is preferably made of a material having a volume resistivity of 10 ¹⁴ Ω · cm or more.

According to this configuration, the unequal electric field is concentrated only on the paint droplets at the tip of the nozzle. As a result, the paint droplets are efficiently charged, and the ability to miniaturize the paint droplets can be improved as compared with the conventional nozzle head. Therefore, the coating processing capacity can be improved as compared with the case where a conventional nozzle head is used.

As one aspect, the nozzle head for an electrostatic atomizing coating machine according to the present invention has a structure in which a first component including the paint chamber and a second component including at least the tip of the nozzle are detachable. preferable.

According to this configuration, when the tip portion of the nozzle, which is more easily damaged than the other portions, is damaged, maintenance such as replacement or repair can be performed only for the first part including the tip portion. Therefore, maintenance is easy.

As one aspect, the nozzle head for an electrostatic atomizing coating machine according to the present invention preferably further includes an on-off valve device capable of opening and closing the base end of a part or all of the plurality of nozzles.

According to this configuration, when the paint spraying on the object to be coated is stopped due to the interruption or termination of the painting work, the on-off valve device is operated to close the connection portion between the base end of the nozzle and the paint chamber. , It is possible to prevent the paint from leaking from the nozzle. This makes it possible to avoid contamination around the nozzle head due to the leaked paint. Further, when painting the end portion of the object to be coated, there may be no object to be coated facing a part of the plurality of nozzles. In such a case, wasteful consumption of the paint can be avoided by closing the connection portion between the base end of the nozzle and the paint chamber where there is no facing object to be coated.

Further features and advantages of the invention will be further clarified by the following illustration of exemplary and non-limiting embodiments described with reference to the drawings.

It is sectional drawing of the side view of the nozzle head which concerns on embodiment. It is a top view sectional drawing of the nozzle head which concerns on embodiment. It is a partial front view of the nozzle head which concerns on embodiment. It is a top view sectional view which shows the attachment / detachment structure of the nozzle head which concerns on embodiment. It is sectional drawing of the nozzle which concerns on embodiment. It is sectional drawing of the conventional nozzle. It is a top view sectional view of the nozzle head which concerns on a modification. It is sectional drawing of the nozzle which concerns on the modification.

An embodiment of a nozzle head for an electrostatic atomizing coating machine according to the present invention will be described with reference to the drawings. Hereinafter, an example in which the nozzle head for an electrostatic atomizing coating machine according to the present invention is applied to the nozzle head 1 for an electrostatic atomizing coating machine that coats an object to be coated by spraying paint will be described.

[Nozzle head configuration]
The nozzle head 1 according to the present embodiment is attached to the opposite side of the main body B connected to the work arm of the painting robot (not shown) on the side opposite to the side connected to the painting robot in the used state (FIG. 1, FIG. Figure 2). 1 and 2 are cross-sectional views of the main body B and the nozzle head 1 attached to the main body B from two directions, and the relationship between the two figures is taken along the lines II-II (FIG. 1) and I in each of the drawings. -Indicated by line I (Fig. 2).

The main body B is formed with a paint supply path P1 and a paint return path P2 that connect the paint chamber 2 inside the nozzle head 1 and the paint supply source (not shown). Further, the paint supply path P1 and the paint return path P2 are provided with a supply side switching valve V1 for opening and closing the paint supply path P1 and a return side switching valve V2 for opening and closing the paint return path P2, respectively. ing.

The nozzle head 1 includes a paint chamber 2, a plurality of nozzles 3, and an electrode 4. Each nozzle 3 communicates fluidly with the paint chamber 2 on the base end 31 side (FIGS. 1 and 2). Further, the plurality of nozzles 3 are provided so that the openings 32a provided on the tip 32 side of each nozzle 3 are arranged in a straight line along the straight line X (FIGS. 1 and 3). When referring to the direction of each part in the following description, the side of the nozzle head 1 where the nozzle 3 is provided (the right side of the paper in FIGS. 1 and 2) is referred to as "front" ("front", "front"". , Etc.), and the side connected to the main body B of the nozzle head 1 may be described as "rear" ("rear", "rear", etc.).

The electrostatic atomization coating machine is equipped with a voltage application device (not shown) that applies a potential difference between the object to be coated and the nozzle head 1, and provides a paint supply path P1, a paint chamber 2, and a nozzle 3. The paint ejected after that is charged by applying a high voltage by this voltage applying device. Further, an electric field is formed around the opening 32a of the nozzle 3 by applying a high voltage by this voltage applying device, and the charged paint ejected from each opening 32a is used as a so-called electrostatic spray to open each opening. The charged paint, which has been refined by the action of the electric field formed around the portion 32a, is electrostatically attracted to the object to be coated by the potential difference between the nozzle head 1 and the object to be coated, and flies. By doing so, it is applied to the surface of the object to be coated.

The nozzle head 1 has a structure in which the first component 11 including the paint chamber 2 and the second component 12 including the tip 32 of the nozzle 3 are detachable (FIG. 4). When connecting the first component 11 and the second component 12, the first component 11 and the second component 12 are fastened using the fixing component 13. As a method of fastening the first component 11 and the second component 12 using the fixing component 13, any known method can be used as a method of connecting the mechanical components, and the structure of the fixing component 13 and the structure thereof. The partial structure of the first component 11 and the second component 12 corresponding to the above is a structure corresponding to the connecting method adopted. For example, it may be a fitting structure, a screwing structure, or the like.

The nozzle 3 is divided into a nozzle portion 3A on the base end 31 side included in the first component 11 and a nozzle portion 3B on the tip 32 side included in the second component 12, and the first component 11 and the second component When the nozzle 12 is fastened, the two nozzle portions 3A and 3B are connected to form the nozzle 3 (FIG. 5). Specifically, a part 33 of the nozzle part 3B protruding from the proximal end side of the second part 12 can be accommodated in the space 11a provided on the extension line of the nozzle part 3A of the first part 11, and the part 33. The two nozzle portions 3A and 3B are connected to each other when the space 11a is inserted all the way into the space 11a (FIG. 4).

(Structure of paint room)
The paint chamber 2 is provided as a substantially rectangular parallelepiped space inside the first component 11 of the nozzle head 1 (FIGS. 1 to 3). The front side of the paint chamber 2 is in fluid communication with the base ends 31 of the plurality of nozzles 3, and the rear side of the paint chamber 2 is in fluid communication with the paint supply path P1 and the paint return path P2. A valve (not shown) capable of controlling the amount of paint flowing into the nozzle 3 is provided inside the paint chamber 2. The valve may be one or a plurality of valves that can collectively control the amount of paint flowing into the plurality of nozzles 3, or individually control the amount of paint flowing into each of the plurality of nozzles 3. It may be a plurality of possible valves.

A plurality of on-off valve devices 21 are provided inside the paint chamber 2. Each on-off valve device 21 may close the connection portion between the proximal end group and the paint chamber over the proximal end 31 (hereinafter referred to as the proximal end group) of a part or all of the plurality of nozzles 3. It is implemented as a valve body. The plurality of on-off valve devices 21 can individually select a posture in which the connection portion between the base end group and the paint chamber 2 is closed or a posture in which the connection portion is opened. By providing such an on-off valve device 21, the on-off valve device 21 is operated to operate the on-off valve device 21 to stop the paint spraying on the object to be coated due to the interruption or termination of the painting work, and the base end group and the paint chamber. By closing the connection portion with 2, it is possible to prevent the paint from leaking from the nozzle 3. This makes it possible to avoid contamination around the nozzle head 1 due to the leaked paint. Further, when painting the end portion of the object to be coated, there is a case where the object to be coated facing a part of the plurality of nozzles 3 does not exist. In such a case, wasteful consumption of the paint can be avoided by closing the connection portion between the base end 31 of the nozzle 3 and the paint chamber 2 in which there is no facing object to be coated.

(Nozzle configuration)
In the present embodiment, the nozzles 3 are mounted as straight pipes having an outer diameter of 0.8 mm, an inner diameter of 0.3 mm, a wall thickness of 0.25 mm, and a length of 60 mm, respectively. The dimensions of the nozzle 3 can be appropriately selected depending on the properties of the paint used (type of solvent, viscosity, solid content concentration, etc.), the size of the object to be coated, and the like. However, the inner diameter of the nozzle 3 is preferably 0.2 to 1.0 mm. Further, the length of the nozzle 3 is preferably 5 to 100 mm.

In the present embodiment, the plurality of nozzles 3 are provided at equal intervals, and the distance between the adjacent nozzles 3 is 3 mm. In this embodiment, 100 nozzles 3 are provided in parallel with each other along the straight line X. By providing a plurality of (100) nozzles 3 in parallel, paint droplets can be ejected from each nozzle 3 in parallel.

In the present embodiment, for the first nozzle 34 and the second nozzle 35 shown in FIG. 1, when the linear rows of the plurality of nozzles 3 are parallel to the vertical direction (the direction in which the plurality of nozzles 3 extend becomes horizontal). When), the difference between the first water head, which is the water head at the connection portion 341 between the first nozzle 34 and the paint chamber 2, and the second water head, which is the water head at the connection portion 351 between the second nozzle 35 and the paint chamber 2. However, it is configured to be within 10% of the second head. Here, the first nozzle 34 is an electrostatic fog when the linear rows of the plurality of nozzles 3 are parallel to the vertical direction (that is, when the postures shown in FIGS. 1 and 2 are taken). The nozzle 3 is arranged at the highest position with respect to the installation surface of the chemical coating machine, and the second nozzle 35 is the nozzle 3 arranged at the lowest position with respect to the installation surface of the electrostatic atomizing coating machine. .. A configuration in which the difference between the first head and the second head is within 10% of the second head can be realized by appropriately selecting the inner diameter and length of the nozzle 3 and the arrangement. In the present embodiment, the nozzles 3 mounted as straight pipes having an outer diameter of 0.8 mm, an inner diameter of 0.3 mm, and a length of 60 mm are linearly arranged at intervals of 3 mm, and the above-mentioned head difference is realized by this configuration. Will be done.

Further, the nozzle 3 has a first portion 36 on the base end 31 side and a second portion 37 on the tip end 32 side (FIG. 5). In the present embodiment, the first portion 36 is a portion made of a weakly conductive resin and having a length of 59 mm, and the second portion 37 is a portion made of an insulating resin and having a length of 1 mm. As is clear from the materials constituting each part, the first part 36 has a certain degree of conductivity, but the second part 37 has substantially no conductivity. The "weakly conductive resin" constituting the first portion 36 means a resin material having a volume resistivity of 10 ¹² Ω · cm or less. However, the first portion 36 may be made of any material having a volume resistivity of 10 ¹² Ω · cm or less, and may be made of metal, for example. The first portion 36 is more preferably made of a material having a volume resistivity of ¹⁰⁸ to 10 ¹² Ω · cm. Further, the second portion 37 may be made of any material having a volume resistivity of 10 ¹⁴ Ω · cm or more.

(Polyde configuration)
The electrode 4 is provided on an extension of each end of a linear row of a plurality of nozzles 3. That is, the electrodes 4 are provided along the straight line X like the plurality of nozzles 3. The electrode 4 is mounted as a metal round bar having a diameter of 0.8 mm and is a conductor. However, the material constituting the electrode 4 is arbitrary as long as it has a volume resistivity of 10 ¹² Ω · cm or less, and may be, for example, a weakly conductive resin in addition to the metal exemplified above.

The electrode 4 is provided at a position adjacent to the first nozzle 34 and the second nozzle 35 along the straight line X. The separation distance between the electrode 4 and the first nozzle 34 and the second nozzle 35 is 3 mm, which is the same as the separation distance between the nozzles 3. Further, the tips of the electrodes 4 and the tips 32 of the plurality of nozzles 3 are substantially on the same plane. That is, the length of the electrode 4 extending forward and the length of the nozzle 3 extending forward are the same (60 mm).

A cap 41 is attached to the tip of the electrode 4. The cap 41 is a bottomed cylindrical body made of an insulating resin and having a wall thickness of 0.5 mm. As is clear from the fact that it is made of an insulating resin, the cap 41 has substantially no conductivity. That is, the tip of the electrode 4 is insulated. The material and dimensions constituting the cap 41 are arbitrary as long as the tip of the electrode 4 can be insulated.

[Action and effect of nozzle head]
Subsequently, the preferable action and effect brought about by the nozzle head 1 having the above configuration will be described.

In the nozzle head 1 according to the present embodiment, since the plurality of nozzles 3 are arranged in a straight line, a coating effect different from that of the conventional nozzle head in which the plurality of nozzles are arranged in an annular shape can be obtained. Specifically, it is easy to make the thickness of the coating film uniform. When using a nozzle head in which the nozzles are arranged in an annular shape, when the nozzle head is swept along the object to be coated, there are places where one nozzle passes and places where two nozzles pass. In some cases, it was difficult to make the thickness of the coating film uniform. However, when a plurality of nozzles 3 are arranged in a straight line, a problem different from that in the case of arranging them in an annular shape may occur.

First, the difference in head between the nozzles 3 becomes a problem because the heights at which the plurality of nozzles 3 are located are different in the used state. The head difference tends to be a problem particularly in the nozzle head in which the nozzles are arranged linearly as in the present embodiment. This is because a nozzle head in which a plurality of nozzles are arranged in a straight line is often required to have a larger coating width than a nozzle head in which a plurality of nozzles are arranged in an annular shape. This is because the distance between both ends is larger than the diameter of the circle in the annular arrangement, which tends to increase the height difference between the plurality of nozzles. When the water head difference between the nozzles 3 is large, the amount of paint discharged may be significantly different for each nozzle 3, which leads to the occurrence of coating unevenness. Therefore, in the present embodiment, the difference between the first head and the second head is set to be within 10% of the second head for the first nozzle 34 and the second nozzle 35, which have the maximum head difference. As a result, the head difference between any nozzles 3 is suppressed to a level that does not cause a problem in use.

Secondly, the uniformity of the electric field formed around each nozzle 3 becomes a problem. When performing electrostatic coating method painting in which charged paint is ejected from multiple nozzles and adhered to the object to be coated, the paint is ejected from each nozzle (size of paint droplets, flight direction, etc.). ) To be uniform and to stabilize the coating quality, it is necessary to make the electrical environment of a plurality of nozzles uniform. In particular, an electric field formed around a specific nozzle is affected by an electric field formed around another adjacent nozzle, so it is normal practice to make the relative positional relationship of multiple nozzles uniform. Will be. In the case of a conventional nozzle head in which a plurality of nozzles are arranged in an annular shape, if the nozzles are arranged at equal intervals, there are other nozzles adjacent to both sides in the circumferential direction for each nozzle, and the relative of the plurality of nozzles. It is easy to solve this problem because the positional relationship becomes uniform.

However, in the nozzle head 1 according to the present embodiment, the nozzle 3 adjacent to the first nozzle 34 and the second nozzle 35 exists only on one side, and the nozzle 3 does not exist on the other side. Therefore, the electric field formed around the first nozzle 34 and the second nozzle 35 can be significantly different from the electric field formed around the other nozzles 3. Therefore, in the present embodiment, an electrode 4 is provided adjacent to each of the first nozzle 34 and the second nozzle 35, and this is used as a substitute for the adjacent nozzle 3. In the present embodiment, since the nozzle 3 is a straight tube having an outer diameter of 0.8 mm and the electrode 4 is a round bar having a diameter of 0.8 mm, the electrical properties of the two can be substantially the same. By providing the electrode 4, the electrical environment of all the nozzles 3 including the first nozzle 34 and the second nozzle 35 can be brought close to uniform. Thereby, the uniformity of the coating film thickness can be improved.

However, if the electrode 4 is provided, an overcurrent abnormality may occur due to a discharge generated from the tip of the electrode 4. Therefore, in the present embodiment, the discharge from the tip of the electrode 4 is suppressed by attaching the cap 41 to the tip of the electrode 4.

As described above, the nozzle head 1 according to the present embodiment solves the peculiar problem that may occur when a plurality of nozzles 3 are arranged in a straight line.

Further, the nozzle head 1 having the above configuration also brings about the following effects. It should be noted that the effects listed below are not limited to the case where the arrangement of the nozzles 3 is linear.

In the nozzle head 1 according to the present embodiment, the second portion 37 (length 1 mm) on the tip 32 side of the nozzle 3 has substantially no conductivity (FIG. 5). As a result, the voltage is applied only to the portion D1 where the paint flows at the tip 32 of the nozzle 3. The portion D1 does not include the actual portion (thickness 0.25 mm) of the nozzle 3. On the other hand, in the conventional nozzle 3'(FIG. 6) in which all the portions including the tip are conductive, a voltage is applied over the portion D2 corresponding to the outer shape of the conventional nozzle 3'. The portion D2 includes a substantive portion of the conventional nozzle 3'. That is, the difference between the two is whether or not the actual portion of the nozzle is included in the portion to which the voltage is applied. Since the purpose of applying the voltage when performing the electrostatic coating method is to charge the discharged paint droplets, it is not necessary that the actual portion of the nozzle is charged at the tip portion of the nozzle. Therefore, in the present embodiment, the second portion 37 is configured not to have conductivity so that the unequal electric field is concentrated only on the paint droplets at the tip 32 of the nozzle 3. As a result, in the nozzle head 1 according to the present embodiment, the paint droplets are efficiently charged, and the ability to miniaturize the paint droplets is improved as compared with the conventional nozzle head.

Since the nozzle head 1 is connected to the voltage applying device via the main body B, it is required that the high voltage applied to the base end 31 side of the nozzle 3 does not decrease as much as possible even at the tip 32. When a material having substantially no conductivity is used for the entire nozzle, the conductive path to the tip of the nozzle is only the paint, and a voltage drop occurs due to the electric resistance of the paint. Therefore, as described above, it is preferable to use a material having substantially no conductivity only in a small portion (second portion 37) on the tip 32 side of the nozzle 3.

In addition, among the parts of the nozzle head 1, the nozzle 3 mounted as a plurality of thin tubes is a place where defects such as wear, deformation, and breakage are particularly likely to occur. Since the nozzle head 1 according to the present embodiment has a structure in which the first component 11 including the paint chamber 2 and the second component 12 including the tip 32 of the nozzle 3 are detachable, a problem has occurred in the nozzle 3. In this case, only the second part 12 can be replaced to repair the defect. This makes it easier to repair defects as compared to conventional nozzle heads with an integrated configuration.

[Other embodiments]
Finally, another embodiment of the nozzle head for an electrostatic atomizing coating machine according to the present invention will be described. The configurations disclosed in each of the following embodiments can be applied in combination with the configurations disclosed in other embodiments as long as there is no contradiction.

In the above embodiment, a configuration in which the plurality of nozzles 3 are provided so that the openings 32a are arranged in a straight line along the straight line X has been described as an example. However, in the present invention, the number of nozzle rows may be singular or plural. For example, in the nozzle head 1'corresponding to the modification shown in FIG. 7, two rows of nozzles 3 are provided.

In the above embodiment, a configuration in which a plurality of on-off valve devices 21 are provided in the paint chamber 2 will be described as an example. However, in the present invention, the on-off valve device may not be provided, and a single on-off valve device capable of opening and closing the connection portion between the nozzle and the paint chamber at once is provided for all of the plurality of nozzles. You may.

In the above embodiment, the configuration in which the second portion 37 on the tip 32 side of the nozzle 3 is made of an insulating resin has been described as an example. However, in the present invention, the tip of the nozzle may have conductivity, that is, the volume resistivity of the tip of the nozzle may be 10 ¹² Ω · cm or less. In this case, unlike the above embodiment, a nozzle made of the same material (material having a volume resistivity of 10 ¹² Ω · cm or less) over the entire length may be used.

Further, when a second portion made of a material having a volume resistivity of 10 ¹⁴ Ω · cm or more is provided at the tip of the nozzle, the method is not limited to the above embodiment. For example, the nozzle 3'' shown in FIG. 8 has a structure in which the nozzle cap 38 is attached to the tip of the conventional nozzle 3'(FIG. 6). The nozzle cap 38 is an annular lid made of a material having a volume resistivity of 10 ¹⁴ Ω · cm or more. By attaching the nozzle cap 38 to the conventional nozzle 3', the part of the conventional nozzle 3'acts as the first part made of a material having a volume resistivity of 10 ¹² Ω · cm or less, and the part of the nozzle cap 38 has a volume resistance. It works as a second part made of a material with a resistivity of 10 ¹⁴ Ω · cm or more. Also in this example, the voltage can be applied only to the portion D1 through which the paint flows, as in the nozzle 3 according to the above embodiment. Further, since the nozzle cap 38 is provided with a hem portion 38a that covers the front end side surface of the conventional nozzle 3', the length of the insulated portion of the surface of the conventional nozzle 3'is long, and a high voltage is applied. Even so, stable painting can be performed.

In the above embodiment, an example is described in which the difference between the first head and the second head is configured to be within 10% of the second head. However, in the present invention, the mutual head difference between the plurality of nozzles is not particularly limited.

In the above embodiment, the configuration in which the electrode 4 is provided on the extension line of each end of the linear row of the plurality of nozzles 3 has been described as an example. However, in the present invention, the electrode may not be provided, or the electrode may be provided only on the extension line of the end of a part of the linear row of the plurality of nozzles. Further, in the above embodiment, the configuration in which the electrode 4 is mounted as a metal round bar having a diameter of 0.8 mm has been described as an example, but the shape of the electrode is not particularly limited. However, it is preferable that the outer shape of the electrode and the outer shape of the nozzle are the same.

In the above embodiment, the configuration in which the cap 41 is attached to the tip of the electrode 4 and the tip of the electrode 4 is insulated by the cap 41 has been described as an example. However, when the electrode is provided in the present invention, the presence or absence of insulation at the tip thereof is not limited.

In the above embodiment, a configuration in which the forward extension length of the electrode 4 and the forward extension length of the nozzle 3 are the same has been described as an example. However, when the electrode is provided in the present invention, its extension length may be shorter or longer than that of the nozzle. Since the flight direction of the paint droplets can be changed by the length of the electrode, it is advisable to appropriately select the length of the electrode according to the coating pattern to be realized. For example, if the electrodes are mounted so as to be movable back and forth along the extending direction, the position (extending length) of the electrodes can be adjusted according to the coating pattern to be realized. Further, if a plurality of electrodes having different lengths are prepared and the electrodes are attached in a detachable manner, the length of the electrodes to be used can be selected according to the coating pattern to be realized.

In the above embodiment, an example in which the nozzle head 1 has a structure in which the first component 11 and the second component 12 are detachable has been described. However, the nozzle head for an electrostatic atomizing coating machine according to the present invention may have an inseparable integrated structure.

It should be understood that with respect to other configurations, the embodiments disclosed herein are exemplary in all respects and the scope of the invention is not limited thereto. Those skilled in the art will be able to easily understand that modifications can be made as appropriate without departing from the spirit of the present invention. Therefore, another embodiment modified without departing from the spirit of the present invention is naturally included in the scope of the present invention.

INDUSTRIAL APPLICABILITY The present invention can be used, for example, as a nozzle head for an electrostatic atomizing coating machine that coats an object to be coated by spraying a paint.

1: Nozzle head 11: First component 11a: Space provided in the first component 11 (a part 33 of the nozzle portion 3B can be accommodated).
12: Second part 13: Fixing part 2: Paint room 21: On-off valve device 3: Nozzle 3A: Nozzle part (base end side)
3B: Nozzle part (tip side)
31: Base end of nozzle 3 32: Tip of nozzle 3 32a: Opening 33: Part of nozzle portion 3B (may be accommodated in space 11a of first component 11)
34: First nozzle 341: Connection part between the first nozzle 34 and the paint chamber 2 35: Second nozzle 351: Connection part between the second nozzle 35 and the paint chamber 2 36: First part of the nozzle 3 37: Nozzle 3 Second part 38: Nozzle cap 4: Electrode 41: Cap B: Main body P1: Paint supply path P2: Paint return path V1: Supply side switching valve V2: Return side switching valve

Claims (8)

A nozzle head for an electrostatic atomizing coating machine equipped with a paint chamber and a plurality of nozzles.
Each of the plurality of nozzles has fluid communication with the paint chamber on the proximal end side.
The plurality of nozzles are nozzle heads for an electrostatic atomizing coating machine provided so that openings provided on the tip side of each nozzle are arranged in a straight line. The plurality of nozzles include a first nozzle arranged at the highest position when the linear row of the plurality of nozzles is parallel to the vertical direction, and a second nozzle arranged at the lowest position. ,
When the linear row of the plurality of nozzles is parallel to the vertical direction, the first head, which is the head at the connection portion between the first nozzle and the paint chamber, and the second nozzle and the paint chamber. The nozzle head for an electrostatic atomizing coating machine according to claim 1, wherein the difference between the second head, which is the head at the connecting portion, and the second head is within 10% of the second head. The nozzle head for an electrostatic atomizing coating machine according to claim 1 or 2, wherein the nozzle has an inner diameter of 0.2 to 1.0 mm and a length of 5 to 100 mm. The nozzle head for an electrostatic atomizing coating machine according to any one of claims 1 to 3, wherein an electrode is provided on an extension line of each end of a linear row of the plurality of nozzles. The nozzle head for an electrostatic atomizing coating machine according to claim 4, wherein the tips of the respective electrodes are insulated. At least one of the plurality of nozzles
It has a first portion on the proximal end side and a second portion on the distal end side.
The first part is made of a material having a volume resistivity of 10 ¹² Ω · cm or less.
The nozzle head for an electrostatic atomizing coating machine according to any one of claims 1 to 5, wherein the second portion is made of a material having a volume resistivity of 10 ¹⁴ Ω · cm or more. The nozzle for an electrostatic atomizing coating machine according to any one of claims 1 to 6, wherein the first component including the paint chamber and the second component including at least the tip of the nozzle have a detachable structure. head. The nozzle head for an electrostatic atomizing coating machine according to any one of claims 1 to 7, further comprising an on-off valve device capable of opening and closing the base end of a part or all of the plurality of nozzles.

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